The hazards to public health and the environment which are posed by a variety of synthetic halogenated organic compounds are well known. Compounds such as polychlorinated biphenyls (PCB's), dibenzodioxins, dibenzofurans, dichlorodiphenyl trichloroethane (DDT), dieldrin, lindane and chlordane, as well as other halogenated pesticides, have been found to be persistent, environmentally toxic materials which require safe and efficient means of disposal. PCB's pose a particularly serious disposal problem. Once widely used as dielectric fluid additives in electrical equipment such as transformers and capacitors because of their excellent insulating properties, the use of PCB's in many applications has been banned by the U.S. Environmental Protection Agency owing to the cumulative storage of PCB's in the human body and the extremely high toxicity of PCB's. PCBs are a class of chemically inert, chlorinated hydrocarbons. It is reported that over a billion pounds of PCBs have been manufactured in the United States, and it is estimated that 300 million pounds of these are in chemical landfills and about 750 million pounds are still in use.
The problems associated with PCB contamination in New Bedford, Mass. (EPA Region I), the Hudson River in New York (EPA Region II), and in Waukegan, Ill. (EPA Region V) are highly publicized to be among the worst in the United States in terms of concentration and total quantity of PCBs. The PCB contamination problems pose threats to both drinking water and the fishing industry. There are also many industrial lagoons contaminated with PCB's. Thus, methods for the removal and/or destruction of halogenated organic compounds such as PCB's are required.
Various methods for the removal and/or the destruction or decomposition of halogenated organic compounds are known in the art. For example, the Peterson U.S. Pat. Nos. 4,447,541 and 4,574,013 disclose methods for decontaminating soil which is contaminated with halogenated organic compounds. The Peterson U.S. Pat. No. 4,447,541 discloses a process in which a reagent mixture of an alkaline constituent and a sulfoxide catalyst (DMSO) are intimately mixed with soil contaminated with PCB's. The reagent mixture affects a desorption of the halogenated contaminants from the soil and subsequently dehalogenates the contaminants. However, this process is disadvantageous in that the kinetics are relatively slow and therefore reduction of the PCB concentration to an acceptable level requires extended time periods ranging from weeks to months, the soil must be completely dry for the destruction to take place, large quantities of the reagent are required, and the sulfoxide catalyst may potentially transport contaminants prior to their destruction. The Peterson U.S. Pat. No. 4,574,013 discloses a process wherein a heated slurry of contaminated soil is treated with a mixture of an alkaline constituent and a sulfoxide catalyst. However, this process is similarly disadvantageous in that the sulfoxide catalyst may transport contaminants into living systems, and the sulfoxide catalyst produces odorous compounds when heated to high temperatures and decomposes into combustible byproducts under elevated temperature conditions. This process is also disadvantageous in that it requires large amounts of reagents.
The Rogers et al U.S. Pat. No. 4,675,464 discloses a method for the chemical destruction of halogenated aliphatic hydrocarbons, and more particularly a method for the chemical destruction of ethylene dibromide. An alkali metal hydroxide is dissolved in an ethylene glycol and the resulting product is reacted with the halogenated hydrocarbon. Rogers et al further disclose that the reaction temperature should be maintained at 30 deg. C. or less to maintain the reaction products in solution.
The Pytlewski et al U.S. Pat. No. 4,400,552 discloses a method for the decomposition of halogenated organic compounds which employs a reagent comprising the product of the reaction of an alkali metal hydroxide with a polyglycol or a polyglycol monoalkyl ether, and oxygen. The Pytlewski et al U.S. Pat. Nos. 4,337,368 and 4,602,994 disclose similar methods of decomposing halogenated organic compounds. Additionally, the Pytlewski et al U.S. Pat. Nos. 4,430,208, 4,417,977, 4,460,797 and 4,471,143 also disclose methods for separation and/or decomposition of halogenated organic compounds. However, these methods are disadvantageous in that excess amounts of the alkali metal hydroxide and polyglycol reagents are required in order to obtain a homogeneous distribution throughout the contaminated material, for example soil, sediment, sludge or the like, which is treated. The Pytlewski et al U.S. Pat. Nos. 4,349,380 and 4,523,043 disclose the use of reagents made from an alkali metal or alkali metal hydroxide and a polyglycol or a polyglycol monoalkyl ether for removing metals from metal-containing materials and for decomposing organo sulfur compounds, respectively. Similarly, the Brunelle U.S. Pat. Nos. 4,351,718 and 4,353,793 disclose methods for removing polyhalogenated hydrocarbons from nonpolar organic solvent solutions by treating the contaminated solutions with a mixture of polyethylene glycol and an alkali metal hydroxide. These methods are similarly disadvantageous in that excess amounts of reagent are required.
Additional methods for removing and/or destructing halogenated organic compounds contained in contaminated materials are disclosed in the Howard et al U.S. Pat. No. 4,327,027, the Heller U.S. Pat. No. 4,483,716, the Mendiratta et al U.S. Pat. No. 4,663,027, the Meenan et al U.S. Pat. Nos. 4,685,220 and 4,793,937, the Rossi et al U.S. Pat. No. 4,761,221, the Zeff et al U.S. Pat. No. 4,792,407, European Patent Application No. 118,858, Chemical Abstracts, Vol. 82, No. 139620P (1975) and Kornel et al, Journal of Hazardous Materials, 12 (1985), pages 161-176. However, these and additional processes known in the art for the removal and/or destruction of halogenated organic compounds in contaminated materials are inadequate in view of the time required for acceptable levels of removal and/or destruction, the use of excessive amounts of various reagents, the use of expensive reagents, the production of toxic and/or combustible byproducts, and/or the failure to obtain desired removal and/or destruction levels. Thus, a need exists for additional methods for the removal and/or destruction of halogenated organic compounds in contaminated materials, which methods overcome the disadvantages of the prior art.
Proteins or prolamines, such as zein, have many utilities due to their amphoteric nature. Proteins have been used in a wide variety of applications including in the production of paper coatings, grease-resistant coatings, laminated boards, solid color prints, printing inks, food coatings, and microencapsulants. Prolamines are substantially insoluble in water and in alcohol but are soluble in alcohol-water mixtures. It is desirable to produce and use these protein complexes in applications such as absorbents, filtering aids, odor suppressants and as a coagulants or clarifying agents, in fluids, especially aqueous, environments to utilize the amphoteric characteristics of the protein components.
It is an object of the present invention to provide a method of processing fluids and particulate solids such as soils containing polychlorinated biphenyls (PCB's), dibenzodioxins, dibenzofurans, dichlorodiphenyl trichloroethane (DDT), dieldrin, lindane and chlordane, as well as other halogenated contaminants and pesticides, with fine to very fine protein-polysaccharide complex composition particles or solutions thereof, to separate off undesired substances contributing to contamination.
It is an object of the present invention to produce a water soluble complex containing both a substantially water insoluble protein and a polysaccharide displaying beneficial characteristics of both proteins and polysaccharides, useful as an adsorbent, coagulant or a clarifying agent, a stabilizing and filtering aid, and as a filter coating having predetermined or predictable physical or chemical properties suitable for specific purposes, so that it is possible, with structurally straightforward apparatus, to carry out qualitatively high value stabilizations, coagulations and separation filtrations.
It is an object of the present invention to provide a process for the production of a protein complex formed by impregnating or coating a polysaccharide with a substantially water-insoluble protein to form an adsorbent, coagulant or a clarifying agent, a stabilizing and filtering aid, and a filter coating for use in separating polychlorinated biphenyls (PCB's), dibenzodioxins, dibenzofurans, dichlorodiphenyl trichloroethane (DDT), dieldrin, lindane and chlordane, as well as other halogenated contaminants and pesticides, and heavy metals.
Accordingly, it is the primary objective of the present invention to overcome these and other prior art disadvantages by providing a composition useful for the decontamination, or detoxification, of contaminated or toxin-polluted streams, and process for the passage of a contaminant-containing or toxin-polluted stream through a bed of said composition to decontaminate or detoxify said stream.
A specific object is to provide novel compositions suitable for use in the continuous decontamination, or detoxification of contaminated, or toxic chemical-containing streams brought into contact therewith at high detoxification rates.
A further object is to provide a process utilizing these compositions, and others, for the decontamination or detoxification of toxic chemical-containing streams contacted therewith.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.